1. Field of the Invention
This invention relates to a cam-locking coupling assembly that couples two tubular members, more particularly to a cam-lock actuating device for use in a locking coupling assembly which is operable to safely connect and disconnect two tubular members.
2. Description of the Related Art
Referring to FIG. 1, a conventional locking coupling assembly is shown to include a cylindrical body 1 connected to a female coupling tube (not shown), a male coupling tube 2 inserted into the cylindrical body 1 and fluid-tightly engaged therewith by means of a seal ring 3, and two cam arms 10 pivotably mounted on two lugs 101 of the cylindrical body 1 by pivot pins 112, respectively. Each of the cam arms 10 has a cam surface 111 extending into the cylindrical body 1 for engaging an annular grooved surface 201 of the male coupling tube 2 when the respective cam arm 10 is at a locking position. A spring-biased lock bolt 12 is movably received in a hole formed in each of the cam arms 10 such that a locking end 121 extends through the hole to be inserted into a locking hole 103 in the cylindrical body 1 for retaining the cam arm 10 at the locking position. A pull ring 14 is attached to the lock bolt 12 such that, by pulling the pull ring 14, the locking end 121 is moved to be disengaged from the locking hole 103 so as to permit turning of the respective cam arm 10 to an unlocking position, where the cam surface 111 is disengaged from the annular grooved surface 201. Thus, the locking coupling assembly can be used to quickly connect and disconnect two tubular members, such as hoses, pipes, etc.
However, since such locking coupling assembly is generally filled with a pressurized fluid in use, once the cam arms 10 are turned to the unlocking position by an operator, the male coupling tube 12 may burst from the internal pressure in the female coupling tube, which may cause injury to the operator. Besides, the pressurized fluid may be ejected from the female coupling tube and pollute the environment.